1. Field of the Invention
The present invention relates to liquid discharge device that discharges liquid from a main tank to a sub tank that is arranged on a carriage.
2. Description of the Related Art
Ink jet printers having a so-called stationary supply mechanism are known. With the stationary supply mechanism, a sub tank that is capable of storing small amount of ink is arranged on a carriage. A print head used to print on the printing medium is also arranged on the carriage. Ink is supplied to the print head from the sub tank. A main tank that is capable of storing a large amount of ink is attached to a position separate from the carriage. The carriage is capable of moving. The movement of the carriage can be controlled easier with lighter load burdened onto the carriage. The sub tank and the main tank are separated in order to lighten the carriage load.
When the carriage moves to an ink supply position, the sub tank and the main tank are temporarily connected with a supply nozzle. The supply nozzle is inserted into the sub tank via a connecting position arranged on the sub tank, and the ink inside the main tank is replenished to the sub tank via the supply nozzle. The aforementioned configuration of the so-called stationary supply mechanism is disclosed in the Japanese Patent Application Publication No. 2001-162830.
In the aforementioned publication, a cover that can be rotated is arranged on the connecting position of the sub tank by using a spring. The supply nozzle is able to push the cover towards its opening direction, and be inserted into the sub tank. After the ink is replenished, as the supply nozzle is withdrawn from the sub tank, the cover is rotated towards its closing direction by the force of the spring.
Furthermore, a technique to connect the supply nozzle by arranging a rubber at the connecting position is taught in the U.S. Pat. No. 6,880,925. In the aforementioned publication, a joint rubber with a cleavage at its center is arranged on a print head. The ink tank, on the other hand, has a supply nozzle to supply ink to the print head. In the course of connecting the supply nozzle to the print head, the supply nozzle is inserted into the cleavage of the joint rubber. The elasticity of the joint rubber maintains the sealing of the print head, even in the course of inserting and withdrawing the supply nozzle.